In response to NIDA's PA 92-110 for "Development of Theoretically Based Psychosocial Therapies for Drug Dependence," a development and pilot evaluation project is proposed for reaching drug dependent individuals through unilateral family intervention with their concerned significant others (CSOs). Although a variety of strategies for counseling CSOs have been widely used in practice, none has been adequately evaluated, and their outcomes are unknown. Further, currently practiced approaches have been largely atheoretical and suggest divergent, even diametrically opposed strategies. Effective intervention through CSOs is likely to: (a) benefit both drug dependent people and their CSOs, as well as their relationships and families; (b) facilitate earlier treatment for or change in drug problems, and (c) provide CSOs with skills for exerting ongoing positive influence following any intervention or treatment. Three inter- related treatment technologies would be developed through the proposed project: (1) a CSO skills-training strategy derived from Azrin's operant "community reinforcement approach" for engaging unmotivated individuals in treatment, which may be particularly appropriate for Hispanic clients (Phase I); (2) adaptation of existing assessment methodologies to evaluate drug problems through CSOs, and (3) a motivational counseling strategy for initiating and consolidating change (Phase II), once contact has been established with an identified patient (IP). Evaluation will address the impact of intervention on the CSO's general functioning, on the IP's drug use and related problems, on treatment-seeking for drug problems, and on family happiness and adjustment including health-care utilization. Key analyses focus on the impact of these strategies, as well as hypothesized markers of favorable response. A range of secondary analyses are proposed, including coding of session videotapes to clarify processes underlying response to Phase I and Phase II modalities.